Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753024AbYKFQsj (ORCPT ); Thu, 6 Nov 2008 11:48:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752567AbYKFQsO (ORCPT ); Thu, 6 Nov 2008 11:48:14 -0500 Received: from mx2.redhat.com ([66.187.237.31]:47155 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752526AbYKFQsL (ORCPT ); Thu, 6 Nov 2008 11:48:11 -0500 Message-ID: <49131FB3.4060807@redhat.com> Date: Thu, 06 Nov 2008 11:47:47 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: Peter Zijlstra CC: Vivek Goyal , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, virtualization@lists.linux-foundation.org, jens.axboe@oracle.com, Hirokazu Takahashi , Ryo Tsuruta , Andrea Righi , Satoshi UCHIDA , fernando@oss.ntt.co.jp, balbir@linux.vnet.ibm.com, Andrew Morton , menage@google.com, ngupta@google.com, Jeff Moyer Subject: Re: [patch 0/4] [RFC] Another proportional weight IO controller References: <20081106153022.215696930@redhat.com> <1225986593.7803.4688.camel@twins> <20081106160154.GA7461@redhat.com> <1225988173.7803.4723.camel@twins> In-Reply-To: <1225988173.7803.4723.camel@twins> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 987 Lines: 30 Peter Zijlstra wrote: > Nice, although I would think only doing the higher level devices makes > more sense than only doing the leafs. I'm not convinced. Say that you have two resource groups on a bunch of LVM volumes across two disks. If one of the resource groups only sends requests to one of the disks, the other resource group should be able to get all of its requests through immediateley at the other disk. Holding up the second resource group's requests could result in a disk being idle. Worse, once that cgroup's requests finally make it through, the other cgroup might also want to use the disk and they both get slowed down. When a resource is uncontended, should a potential user be made to wait? -- All rights reversed. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/